Vacuum cleaner with battery management system

Abstract

A vacuum cleaner includes a cleaner main body including a suction motor for generating a suction force; a suction unit that is in communication with the cleaner main body and sucks air and dust; and a battery that supplies power to the suction motor. The vacuum cleaner also includes a battery management system (BMS) that detects a status of the battery; and a controller that controls an operation of the suction motor. If a voltage of the battery detected by the BMS reaches a changeable reference voltage, the controller stops the suction motor.

What is claimed is: 
     
       1. A vacuum cleaner comprising:
 a cleaner main body having a motor that generates a suction force; 
 a suction unit that is in communication with the cleaner main body and sucks air and dust based on the suction force; 
 a battery that supplies power to the motor; 
 a battery management system (BMS) that detects a status of the battery; and 
 a controller that controls an operation of the motor, 
 wherein, when the motor is operating based on power supplied from the battery, the motor is stopped when a voltage of the battery detected by the BMS changes to be less than a reference voltage, and the reference voltage is changed based on a condition of the battery, 
 wherein when the condition of the battery changes, the reference voltage at which an operation of the motor is stopped is changed from a first voltage to a second voltage that is lower than the first voltage, 
 wherein the condition of the battery changes when a number of times of usage of the battery is increased, 
 wherein the battery comprises a plurality of battery cells and the first voltage is a voltage that is 75% or more of a voltage of all of the battery cells or a voltage that is 75% or more of a maximum voltage of each of the plurality of battery cells, 
 wherein the second voltage is a voltage that is 45% or more of the voltage of all of the battery cells or a voltage that is 45% or more of the maximum voltage of each of the plurality of battery cells, 
 wherein a maximum output of the motor is greater than or equal to 600 W, 
 wherein a maximum charging voltage of the battery is greater than or equal to 84.8V, and 
 wherein a minimum current to operate the motor is less than 7.1 A. 
 
     
     
       2. The vacuum cleaner according to  claim 1 , wherein the battery comprises a plurality of battery cells, and the BMS manages discharging of each of the plurality of battery cells so that power is supplied to the motor from each of the plurality of battery cells. 
     
     
       3. The vacuum cleaner according to  claim 2 , wherein the BMS detects a respective voltage of each of the plurality of battery cells, and the motor is stopped when the voltage of any of the plurality of battery cells is less than or equal to the reference voltage. 
     
     
       4. The vacuum cleaner according to  claim 2 , wherein the BMS detects a respective voltage of each of the plurality of battery cells, and the motor is stopped when the voltage of each of the plurality of battery cells is less than or equal to the reference voltage. 
     
     
       5. The vacuum cleaner according to  claim 1 , wherein the reference voltage is changed when the number of times of usage of the battery exceeds a reference number. 
     
     
       6. The vacuum cleaner according to  claim 1 , wherein the reference voltage is changed when an accumulated usage time of the battery exceeds a reference accumulated time. 
     
     
       7. The vacuum cleaner according to  claim 1 , wherein the reference voltage is changed when a voltage reduction rate according to a discharging time is larger than a reference rate for discharging of the battery. 
     
     
       8. The vacuum cleaner according to  claim 1 , wherein the reference voltage is changed when a voltage increase rate according to a charging time is smaller than a reference rate for charging of the battery. 
     
     
       9. The vacuum cleaner according to  claim 1 , wherein the reference voltage is changed when a charging time during which a predetermined amount of current charges the battery is longer than a reference charging time for charging of the battery. 
     
     
       10. The vacuum cleaner according to  claim 1 , wherein the reference voltage is changed when a one-time available time of the battery is less than or equal to a reference usage time for discharging of the battery. 
     
     
       11. The vacuum cleaner according to  claim 1 , further comprising:
 a charging device separably connected to the cleaner main body and that charges the battery; and 
 a boosting device that boosts a voltage output from the charging device and supplies the boosted voltage to the battery. 
 
     
     
       12. The vacuum cleaner according to  claim 1 , further comprising:
 a charging device provided in the cleaner main body and configured to charge the battery; and 
 a power cord separably connected to the cleaner main body and that supplies external power to the charging device. 
 
     
     
       13. The vacuum cleaner according to  claim 1 , further comprising a display unit that displays information to charge the battery, or an informing unit from which a voice is output, when the motor is stopped.